Portable heating apparatus



March 8, 1949. L. A. WILLIAMS, JR

PORTABLE HEATING APPARATUS 2 sheets-sheet 1 Filed Aug. 24, 1942 March 8, 1949. A. WILLIAMS, JR

PORTABLE HEATING APPARATUS 2 Sheets-Sheet 2 Filed Aug. 24, 1942 Patented Mgr. s, 1949 2,484,165 PORTABLE HEATING APPARATUS Lynn A. Williams, Jr., Northfield, Ill., assignor to Stewart-Warner Corporation,- Chicago, 111., a corporation of Virginia Application August 24, 1942, Serial No. 455,832

4 Claims. 1

aiy invention relates generally to heating apparatus, and more particularly to an improved pertabie heater adapted for emergency use by the crews of aircraft.

Occasionally, planes are forced to land due to failure o'f a part of the airplane, which may be repaired to recondition the plane for flight, but if, for example, the forced landing occurs in winter in the Arctic, with prevalent sub-zero temperatures, the engines may have become cooled to atmospheric temperature by the time the necessary repairs have been completed, and it may be very diiiicult to start them.

Itis therefore an object of my invention to provide a small, compact, emergency heating unit which may be carried on the aircraft, and utilized to provide heat to facilitate repair operations andv warm up the engines preliminary to starting them.

A further object is to provide a small, portable recessed to provide space for a housing i4 of a blower I6, which may be spot-welded, or otherwise suitably secured vto the tank l0, as by ears I8. The rotor of the blower i6 is manually driven by a crank detachably secured to a gear 22 xed to a shaft 24. This shaft is mounted for rotation in suitable bearings formed in extensions oi the side walls of the blower casing I4. The gear 22? meshes with a pinion 28 secured to the rotor shaft 3U of the blower i6.

The outlet of the blower is formed by a condultr32 which may be in part integral with the housing I4, and which contains a carbureting tube emergency heater which may be used, by the crew f of an airplane which has been forced to land, to cook food and to supply heat for the comfort of the crew, and for other purposes.

A further object is to provide a simple handoperated heating apparatus which may be utilized for thawing out and heating aircraft parts and oil tanks and in general for locally applying blasts of heated air for the rapid heating or drying of various materials and'apparatus.

Other objects will appear from the following description, reference being had to the accompanying drawings, in which:

Fig. 1 is a diagrammatic side elevational view of an airplane showing the emergency heater in use;

Fig. 2 is a side elevational view of the heater;

Fig. 3 is a plan view thereof;

Fig. 4 is a fragmentary sectional view taken on the line 4--4 of Fig. 3;

Fig. 5 is a side elevational view, with portions in section, of a modified form of the heating apparatus;

Fig. 6 is a front elevational view of the structure shown in Fig. 5;

Fig. 7 is a fragmentary sectional view taken on the line 1 1 of Fig. 5; and,

Fig. 8 is an elevational view with parts thereof in section showing an improved discharge nozzle for the end of the heated air conveying hose.

The heater comprises a tank I0 for containing the liquid fuel, preferably gasoline, because it is usually readily available, or some other light hydrocarbon fuel. The tank may be lled upon removal of a filling cap l2. The side of the tank is 33 of a burner 34. This burner 3 may be of the type more fully disclosed in the copending application of Henry J. DeN. McCollum, Serial No. 437,557, filed April 3, 1942, now Patent #2,410,547. It will be noted, however, that for the sake of simplicity, no electrical ignition means are provided, but instead the burner may be ignited by dropping a lighted match through a small opening 3B leading to a combustion chamber 38.

Fuel is supplied to the carbureting tube :i3 through a tube 4B, extending to a point near the bottom of the tank l0, and having an opening 42 facing in the direction in which the air flows past it, while a short tube 44 has an opening S6 facing in the direction from which the air is supplied by the blower I6. It will be understood that the blower i6 supplies air for mixture with the combustible iiuid in the tube 33, (and which is subsequently burned in the combustion chamber 38), and also supplies air in a stream flowing around the tube 34 and combustion chamber 38, and thereafter through a heat exchanger 48. The provision of the heat exchanger 48 is optional. When it is used, the products of combustion likewise flow through it and may subsequently be mixed with the air supplied to the heat exchanger 48 so as fully to utilize the generated heat.

Whenever the heated air is to be used for heating a cabin, or used for other purposes in which the heated air must be fresh, the heat exchanger 48 must be used and may be provided with a three-way valve 41 which has its inlet port connected to the outlet end of the heat exchanger. One of the two outlet ports of the valve is connected to an exhaust stack 49 which vents the noxious gases to the atmosphere; the other outlet port directs the products of combustion into the heated air stream. The valve 4l is operated by a crank arm 5|. When it is unnecessary for the heating apparatus to supply pure heated air, the valve may be set to pass the exhaust gases into the stream of heated air. Of course, if it is not.

arrears@ drical shape.

The tank I is also provided with a wick sup-A porting structure 54, which is suitably secured within the tank |0, and has its adjusting thumb nut 56 extending therefrom, by which the position of a wick 58 may be adjusted. The wick A,supporting structure 54 is surrounded by a threaded tube 60 which may be welded to the tank |0, and is normally covered by a cap 62 which has wings 64 formed thereon so that the cap may be screwed down tightly against a gasket 66 under normal conditions, and thereby prevent leakage of fuel from the tank I0. l

Surrounding the threaded tube 60, is an apertured shield 68 which protects the flame from the wind. Across the top of the shield 68 is a suitable grating structure 10 which may be utilized to support small cooking utensils.

The tank l0 is provided with a suitable handle 12 by which the assembly may be conveniently carried, and is also provided with a clamp bracket 14, which may be either permanently secured to the tank I0 or detachably secured thereto by means of butterfly headed studs 16, the bracket 14 being provided with a suitable screw clamp 18.

The tubes 40 and 44 are preferably of capillary dimensions so that even though the heater assembly is lying on its side, no appreciable amount of fuel will leak therefrom, it being only when the fuel is subjected to a substantial pressure differential, due to the Pitot tube effect, that the fuel will be caused to flow through the tube 40 at any substantial rate. Thus, it will usually not be necessary to provide shut-olf valves in these tubes.

When it is desired to heat the engine or other part of an airplane, the flexible hose 52 is withdrawn from its casing 50 and the tank |0 clamped to a convenient part of the airplane by means of the screw clamp 18, whereupon, the operator will commence operating the blower by rotating the crank 20 counterclockwise and will ignite the mixture formed in the burner tube 34, by dropping a lighted match through the opening 36. The mixture will burn in the combustion chamber 38 and flow through the heat exchanger 48 to heat the remainder of the air supplied by the blower I6, the products of combustion being preferably admixed with such air to flow through the hose 52 to the space to be heated. As indicated in Fig. l, the heater may be used to warm up the engine, the cowl opening of which is preferably suitably covered to prevent rapid escape of the heated air supplied by the heating apparatus.

When the pilot is forced to land in a barren terrain, he may unscrew the cap 64 and ignite the Wick 58 and utilize the heat thus attained, to' cook food. The wick is preferably of close tight weave of materials suited to the fuel to be used.

In the modification of the invention shown in Figs. to 8, a blower casing 80, having a screened inlet opening 8|, is suitably secured to a housing 82, which is divided by partition 84 to form a compartment 86 for speed increasing gearing and a tank 90 for the fuel. The speed increasing gearing connects a shaft 92 with the impeller or rotor 84 of the blower. .A crank 96 is secured to the shaft 92 and has a handle 96 swiveled thereto. A heater tube i00 may be formed in two halves integral with the halves of the blower casing 80, there being a discharge port |02 of reduced crosssectional area connecting the interior of the blower with the space within the heater tube |00. Adjacent this restricted discharge port |02 is located a pair of tubes |04, |06, with their open ends directed into the stream of air flowing through the port |02 so as to be supplied with air under substantial pressure due to the velocity pressure head. The tube |04 is connected to the upper end of the tank 80, while the tube |06 is connected to the upper end of a carburetor float bowl |08. A fuel strainer ||0 has its inlet connected to the tank by a pipe to receive fuel therefrom and has its outlet connected to the float bowl |08 by a tube ||2.

Fuel is withdrawn from the float bowl |08 by a conduit ||4, which extends through the heater tube |00 and into the throat portion of a Venturishaped passageway formed in a burner ||6. The end of the tube ||4 within the burner tube ||6 is closed, but is provided with a plurality of radial jet ports ||8 of small diameter. The air inlet of the burner tube I'IB is provided for by a louvered cap |20, the louvers of which are conformed, as best shown in Fig. 7, to cause the air entering its ports to flow in a spiral helical path. A similar louvered cap |22 is provided at the outlet of the Venturi-shaped passageway through the burner tube ||6 so that the mixture of fuel and air fiowing into a combustion chamber |24 will be thoroughly mixed therein due to its rotary helical motion.

A reigniter element |26 is secured to the cap |22, as by welding. This reigniter element may be of the construction disclosed in the copending application of H. J. De N. McCollum, Serial No. 410,039, filed September 8, 1941, now Patent #2,396,868. l

The burner tube I6 is preferably made of a metal having good heat conducting properties, and is preferably of relatively thick section around the Venturi-shaped passageway so that heat will be conducted from the walls of the combustion chamber portion of this element to the air flowing through the Venturi-shaped passageway to pre-heat the latter and thus improve combustion of the mixture. The burner tube ||6 is suitably supported within the heater tube |00 by brackets |28.

Detachably secured to the end of the heater tube |00, as by a snap latch |30, is a collapsible hose |32. This hose |32 is preferably made of a heat resistant fabric which is reinforced by a spiral spring |34, the fabric being impregnated with a suitable composition to make it substantially air-tight.

Secured to the outer end of the discharge hose |32 is a nozzle |36, which has a Venturi-like throat portion provided with apertures |38. The nozzle may be provided with a suitable handle |40 and D-rings |42 for convenience in attaching the nozzle to apparatus to be heated.

The apparatus as a whole is rigidly supported on a base |44 by supporting brackets |46 bolted to the base.

In using the apparatus of Figs. 5 to 8, it is necessary merely to turn the crank 96, whereupon, due to the speed increasing gear train, the blower impeller will be rotated at high speed and draw air through its screened inlet opening'8l. The pressure developed at the discharge port |`02 5 is conducted to the top of the fuel tank 90, thus assuring rapid flow of the fuel therefrom through tbe strainer H and into the float bowl |08. The

air pressure at the throat |02 is likewise transmitted through the tube |06 to the top 0f the fioat bowl to provide pressure for the flow of the fuel therefrom to the low pressure jet orifices |8 formed near the end of the tube ||`4. As soon as dow of fuel has thus been established by operation of the blower, the hose |32 being removed, the fuel mixture may be ignited by a match. As soon as steady combustion has been attained, the hose |32 may be attached to the heater tube H0. The'combustion will take place mainly within the combustion chamber |24, and air flowing around the burner tube H6 will mix with the products of combustion, assuring complete combustion thereof, and the mixture of air with the products of combustion will flow through the hose 32 to the nozzle |36. The nozzle |36 is detachably secured to the end of the hose |32, and is used whenever the blast of air is required to be at a temperature lower than that at ywhich the mixture flows through the hose |32.

Thus, when the nozzle |35 is used, atmospheric air enters the ports |38 and mixes with the gases supplied from the hose |32 to dilute the latter and reduce its temperature to the required extent. Particularly when the apparatus is used for heating oil contained in rubber tanks, and for other similar purposes, it is very desirable to dilute the gases discharged from the hose |32 to prevent scorching or burning of the tank or other equipment or apparatus being heated. )Y

While the apparatus is in operation, the reigniter |26 is heated to a temperature sumciently high to cause reignition of the combustible mixture supplied to the combustion chamber should the operator temporarily neglect to turn the crank 95 at sufficiently high speed to keep the flow of combustible mixture at a rate adequate to maintain the flame.

From the foregoing, it will appear that the apparatus of Figs. to 8, as well as that shown in Figs. 1 to 4, provides a compact efficient apparatus for supplying a large quantity of heated air for local application to a part or apparatus to be heated. and that the apparatus is so simple and so constructed that it will operatesatisfactorily over long periods of time. The apparatus is extremely light in weight compared to the heat output capacity thereof, so that it is practical to utilize it as an auxiliary heating apparatus for aircraft.

While I have shown and described particular embodiments of my invention, it will be apparent to those skilled in the art that the essential features thereof may be embodied in varied and modified forms. I therefore desire to include within the scope of the following claims, all such modifications and variations of the invention whereby substantially the results of the invention may be obtained through the use of substantially the same or equivalent means.

I claim:

1. In a portable emergency heating apparatus, a combination of a tank for liquid fuel, fuel and air mixing means carried by said tank, manually operated means for supplying air-to said mixing means, said mixing means including a Pitot tube positioned so as to be responsive to the air flow rate from said manually operated means and extending to said tank for creating pressure on the fuel therein, a combustion chamber receiving the fuel and air mixture from said mixing means.

2. A portable heating apparatus comprising a blower, manually operable means for driving said blower, a fuel supply tank, a float bowl connected to receive fuel from said tank, a fuel burner supplied with air for combustion by said blower and fuel from said float bowl, means for supplying air under pressure from said blower to said tank thereby to cause fuel to iiow to said float bowl, and means for supplying air under pressure from said blower to said float bowl thereby to cause fuel to ow to said burner.

3. A portable heating apparatus comprising a supporting framework, a fuell tank carried by said framework, a manually operable blower secured to said framework, a fuel burner, means for conducting air from said blower to said burner, a fuel level maintainingfloat bowl adjacent said burner, means for conducting fuel from said tank to said float bowl and from the latter to said burner, a pair of conduits each having one end subjected to the dynamic pressure of the air supplied by said blower, one of said conduits being connected to said fuel tank and the other of said conduits being connected to said float bowl, whereby fuel will flow under pressure from said tank to said float bowl and from said float bowl to said burner.

4. In an apparatus for heating an object by means of a blast of heated gases having a burner for 4the combustion of' fuel, the combination therewith of a flexible extensible conduit having its inlet end connected to the burner for supplying gases to the object to be heated, and a nozzle at the outlet end of said conduit, said nozzle having a Venturi-shaped passageway for the flow of gases therethrough and having ports for the admission of atmospheric air to said gases for admixture therewith to reduce the temperature thereof.

LYNN A. WILLIAMS, Jn.

REFERENCES CITED The following references are of record in the file of this patent:

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